I have recently inquired about getting new adequate ductwork when i have my new furnace/ac unit installed. I was told by the installer that all the duct will be the flexible type. I've put the project on hold until i hear from youall on the mtn top. Does this sound right???I thought it could only be used in certain instances and lengths. What do the experts think????

03-15-2005, 12:42 PM

Gunnery Sergeant Hartman

It'll be fine as long as its designed by Manual D.

03-15-2005, 12:53 PM

dash

Flex will be fine,IF ,sized and installed properly,which is often ,Not the case.

Ask if they are using ManJ and Man. D??

Why are they suggesting replacing all the duct??What is not adequate??

03-15-2005, 01:23 PM

duc dowg

nothing wrong with flex if straped up and seald good
does need to be sized right man d or j

03-15-2005, 01:41 PM

md master

Depends on the application as well. Is it in a crawl space? if so the mice (all homes get em) will eat holes in them and make nests. This will obviously cause a serious leakage as well.

03-15-2005, 02:11 PM

ct2

The company I work for does nothing but residential installations and thats all they use

03-15-2005, 03:06 PM

coolestacman

I think the least amount of flex is best, origanly you use to see it to make the connection from the run to the difuser and a max of three feet. As with everything that comes alon to make ones life easier someone has to abuse it.

If the contractor wants to use flex send him away and get someone that can fab up duct. This would mean getting a reputable shop.

coolestacman

03-15-2005, 03:18 PM

md master

Quote:

Originally posted by coolestacman

If the contractor wants to use flex send him away and get someone that can fab up duct. This would mean getting a reputable shop.

coolestacman

Be prepared for higher prices, quality ain't cheap.

03-15-2005, 03:54 PM

tinknocker service tech

true tinknockers are becoming a thing of the past in the resadential market. flex is fine as long as it is in your attic. if you main trunk is under the house in a crawl or basement should be all medal. and insulatated in all crawl spaces.

03-15-2005, 04:31 PM

rimek

"Depends on the application as well. Is it in a crawl space? if so the mice (all homes get em) will eat holes in them and make nests. This will obviously cause a serious leakage as well."
__________________

See if you can get clear flex for the "habitrail" effect, then.

03-15-2005, 05:33 PM

tinner73

all flex would never pass code by me. you're an ironworker......put some iron in. keep the flex down to a minimum.

03-15-2005, 05:43 PM

beenthere

We prefer to run duct board trunk, then flex to the grilles, but if sized right nothing wrong with flex trunk.

Of course, sheet metal sized wrong is no better then flex sized wrong.

03-15-2005, 07:00 PM

Irascible

Quote:

Originally posted by coolestacman
If the contractor wants to use flex send him away and get someone that can fab up duct. This would mean getting a reputable shop.

Uh huh.

You might consider sending all union shops away too judgetc. A reputable shop has quality employees who are hired and paid on merit - not protected by irrelevant measures such as length of time served, how loud they can yell the word “scab” or what union boss they've sucked up to.

Yeah. I know. Such an analysis is absurd. But it's no more absurd than assuming that sheet metal is the only viable duct solution and that any shop using flex is therefore not reputable.